What are the reasons that allowed the United States to become the new leader of Western civilization?

The formation of the United States as the leader of the Western bloc began in the years following the First World War. Then the United States of America became the main creditor for European states, despite the fact that they themselves were practically not affected during the war years. The continuation was the Second World War, in which the United States also did not need to restore the economy from the ruins, moreover, during the war years, they had a significant number of military orders. Taken together, these two wars gave impetus to the fact that European countries, even having launched integration processes to create a European community, are losing leadership in the Western bloc, giving it over to the United States.